Is whole-colon investigation by colonoscopy, computerised tomography colonography or barium enema necessary for all patients with colorectal cancer symptoms, and for which patients would flexible sigmoidoscopy suffice? A retrospective cohort study

Abstract

BackgroundFor patients referred to hospital with suspected colorectal cancer (CRC), it is current standard clinical practice to conduct an examination of the whole colon and rectum. However, studies have shown that an examination of the distal colorectum using flexible sigmoidoscopy (FS) can be a safe and clinically effective investigation for some patients. These findings require validation in a multicentre study.ObjectivesTo investigate the links between patient symptoms at presentation and CRC risk by subsite, and to provide evidence of whether or not FS is an effective alternative to whole-colon investigation (WCI) in patients whose symptoms do not suggest proximal or obstructive disease.DesignA multicentre retrospective study using data collected prospectively from two randomised controlled trials. Additional data were collected from trial diagnostic procedure reports and hospital records. CRC diagnoses within 3 years of referral were sourced from hospital records and national cancer registries via the Health and Social Care Information Centre.SettingParticipants were recruited to the two randomised controlled trials from 21 NHS hospitals in England between 2004 and 2007.ParticipantsMen and women aged ≥ 55 years referred to secondary care for the investigation of symptoms suggestive of CRC.Main outcome measureDiagnostic yield of CRC at distal (to the splenic flexure) and proximal subsites by symptoms/clinical signs at presentation.ResultsThe data set for analysis comprised 7380 patients, of whom 59% were women (median age 69 years, interquartile range 62–76 years). Change in bowel habit (CIBH) was the most frequently presenting symptom (73%), followed by rectal bleeding (38%) and abdominal pain (29%); 26% of patients had anaemia. CRC was diagnosed in 551 patients (7.5%): 424 (77%) patients with distal CRC, 122 (22%) patients with cancer proximal to the descending colon and five patients with both proximal and distal CRC. Proximal cancer was diagnosed in 96 out of 2021 (4.8%) patients with anaemia and/or an abdominal mass. The yield of proximal cancer in patients without anaemia or an abdominal mass who presented with rectal bleeding with or without a CIBH or with a CIBH to looser and/or more frequent stools as a single symptom was low (0.5%). These low-risk groups for proximal cancer accounted for 41% (3032/7380) of the cohort; only three proximal cancers were diagnosed in 814 low-risk patients examined by FS (diagnostic yield 0.4%).LimitationsA limitation to this study is that changes to practice since the trial ended, such as new referral guidelines and improvements in endoscopy quality, potentially weaken the generalisability of our findings.ConclusionsSymptom profiles can be used to determine whether or not WCI is necessary. Most proximal cancers were diagnosed in patients who presented with anaemia and/or an abdominal mass. In patients without anaemia or an abdominal mass, proximal cancer diagnoses were rare in those with rectal bleeding with or without a CIBH or with a CIBH to looser and/or more frequent stools as a single symptom. FS alone should be a safe and clinically effective investigation in these patients. A cost-effectiveness analysis of symptom-based tailoring of diagnostic investigations for CRC is recommended.Trial registrationCurrent Controlled Trials ISRCTN95152621.FundingThis project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full inHealth Technology Assessment; Vol. 21, No. 66. See the NIHR Journals Library website for further project information.

Faecal immunochemical testing and blood tests for prioritization of urgent colorectal cancer referrals in symptomatic patients: a 2-year evaluation

“…Data were segmented and analysed by fHb according to the cut-offs used during a pilot study 9 and subsequent iterations of pathway, as described above and elsewhwere 11 , 18 . For the primary analyses, fHb below 4, 4–9.9, 10–99.9 and 100 µg Hb/g faeces or above were used.…”

GP access to FIT increases the proportion of colorectal cancers detected on urgent pathways in symptomatic patients in Nottingham

“…Segmentation and stratification of the Primary care population is key to improving early diagnosis for CRC. Simple measures such as a Full Blood Count (FBC) can identify markers such as anaemia [5][6][7] and thrombocytosis 8 that may have value. However, testing for occult blood in faecesthe basis of BCSPcurrently holds much promise.…”

Clinical assessment to determine the risk of bowel cancer using Symptoms, Age, Mass and Iron deficiency anaemia (SAMI)

“…This study, once again, shows that relatively small numbers of cancers proximal to the sigmoid colon are referred to outpatients, and most that are referred have a mass or IDA. This means that after a normal finding on flexible sigmoidoscopy, careful selection for WCI is required to avoid overinvestigation.…”